From Joomla! Documentation
The "API16" namespace is an archived namespace. This page contains information for a Joomla! version which is no longer supported. It exists only as a historical reference, it will not be improved and its content may be incomplete and/or contain broken links.
|objectToString||Converts an object into an XML formatted string.
If more than two levels of nested groups are necessary, since INI is not useful, XML or another format should be used.
|stringToObject||Parse a XML formatted string and convert it into an object.|
jimport( 'joomla.registry.format.xml' );